1. Field
Aspects of the present invention relate to a flat panel display (FPD) with a built-in touch screen and a method of driving the same, and more particularly, to an FPD with a photo sensor type built-in touch screen capable of performing a scanning operation and a method of driving the same.
2. Description of the Related Art
A touch screen is provided on a top surface of an image display device so that a person may select instruction contents displayed on the screen of the image display using a hand or an object contacting the touch screen. The touch screen grasps a contact position and the image display receives the content instructed by the contact position as an input signal to be driven in accordance with the input signal. The image display device having the touch screen is not driven by an additional input device, such as a keyboard or a mouse, coupled to the image display device, and thus, use of the image display having the touch screen is increasing.
Recently, the touch screen is widely used for the FPDs such as a liquid crystal display (LCD), an organic light emitting display (OLED), or other similar display devices. The FPD having the touch screen includes a display panel for displaying an image and a touch screen panel provided on the display panel to detect position information through touch input from a user.
At this time, in order to position the touch screen panel on the display panel, a frame or an adhesive by which an air layer is generated between the display panel and the touch screen panel is used.
In this case, the air layer having a refractive index different from a refractive index of the display panel and the touch screen panel is generated between the display panel and the touch screen panel so that the entire optical characteristic of the FPD deteriorates.
In addition, since an additional touch screen panel is manufactured to be attached to the display panel, manufacturing costs increase and the thickness of the FPD increases.
Therefore, an FPD with a built-in touch screen having the touch screen panel and the display panel are integrated with each other is beneficial.
On the other hand, a photo sensor may be used to detect position information through a touch input from a user. In this case, the part on which external light is incident is distinguished from the part concealed with a contact object such as a hand or a touch stick through the photo sensor to sense a touch position.
In the case of the photo sensor type touch screen, when the object to be scanned is put on the photo sensor type touch screen, when light is radiated on the object using the display panel, light from the display panel is reflected from the object to be scanned to be incident on the photo sensor so that a scanning operation may be performed.
In order to perform the scanning operation in high resolution, a plurality of photo sensors are provided. However, in the case of the FPD with the built-in touch screen, when the number of photo sensors in comparison with the number of pixel units increases, an emission region may be reduced. Therefore, a method of improving scan resolution in comparison with the number of photo sensors is beneficial.